Abstract

Color Removal and COD Reduction of Dyeing Bath Wastewater by Fenton Reaction

Farouk KM Wali

Wastewater produced from Al-Amel dyeing bathes was subjected to Fenton oxidation and three commercial disperse dyes were selected for this study. The selected dyes were, Disperse Yellow 23, Disperse red 167 and Disperse Blue 2BLN, which used for dying cellulose fibers. At first, the optimum conditions for removing dyes from their aqueous solutions were determined and found to be 3 g/l H2O2, 120 mg/l ferrous sulfate hepta hydrate, pH 3 and retention time of about 100 minutes; these conditions achieve color removal of dyes reach 94% from their aqueous solution.
For the treated wastewater, it's found that color removal for Disperse Yellow 23, Disperse red 167 and Disperse Blue 2BLN was 84.66%, 77.19% and 79.63% respectively after retention time 160 minutes. Chemical oxygen demand (COD) measurements indicate that Fenton reaction shows a very good reduction of COD, this was 75.81%, 78.03% and 78.14% for Disperse Yellow 23, Disperse red 167 and Disperse Blue 2BLN respectively. These results strengthen the using of Fenton reaction as a preliminary treatment prior to biological treatment for this wastewater.